Automatic control means for deicing mechanisms for aircraft



H. E. BAER 2,165,198

AUTOMATIC CONTROL MEANS FOR DEICING MECHNISMS FOR AIRCRAFT July 11, 1939.

Original Filed Dec. 14, 1935 o 0 o 0 0 o 0 T INVENTOR. Howard E. aef WWWm/ ATTORNEY.

mechanism had to be manually started andV Patented VJuly 1l, 1939 UNITED y s'rAlss 13A-TENT A OFFICE VAUTOMATIC,(JONI'ILOL MEANS- FOR DEICING j y MECHANlSMB FOB Howard E. Baer,` Garfield; N. J., assigner" to Eclipse Aviation Corporation, East Orange, N. J., a corporation of New Jersey Application December 14, 193s. serial No. 54,4s1

. Renewed April 22, 1938 and tail structure. 'I'hese surface'covenngs'are composed of several layers of rubb'er'and fabric which form tubularair cells. The coverings are tted to the surfaceof the aircraftso that the cells are parallel to the surfaces which .are to be protected. The removal of ice 4formation -is accomplished by periodically inilating and deflating the tubular cells, the constant movement of the surface coverings andthe stretching of the rubber breaking the ice which is then carried away by the air stream; 'i

An aircraft installation normally'consists of an engine driven. air pump, an oil separator and a distributing valve used in conjunction'with the de-icers. The engine driverrair pump provides the necessary air pressure to inflate the air cells of the de-icers. The oil separator removes the oil vapor from the air supplied 'by the pump and also regulates the air pressureto thejde-icer air cells. From the oil separator the air pressure is transmitted to a distributingvalve which, as it rotates, controls the periodic inilationand deation of the de-icer aircells.

Heretofore, de-icing mechanisms of the above type had to be manilly controlled, i. e., the

stopped thereby requiring lthe pilots attention and judgment as to when the de-icing mechanism should be started inoperation. lSometimes it is diilicult to 'ascertain just when ice is forming on the aircraft surface and, hence, the pilot may not be vaware'of the' fact that ice is forming on his ship until he begins tol note a loss of altitude or diculty in maneuvering his ship.A

It is, therefore, one of the objects of the present invention to provide novel means forautomatically starting d'e-iclng mechanismof the class described when icebegins to form on the wings or 'other surfaces of thev aircraft, whereby the" pilot is relieved of the necessity of observing an aircraft, de-icingvmechanismfor preventing ice formation lon surfaces `of the 'craft or if ice is formed-for breaking up sach ice formation, andL -in'eans for automatically rendering such de-icing mechanism operative when ice begins to form on said surfaces.

Still another object of the invention isv to provide a novel combination including an aircraft having a de-icing mechanism, and means respon- A siveto ice formation-for rendering said de-icing mechanism operative whereby suchy mechanism is automatically started whenv ice forms or tends to form von surfaces ofthe aircraft.

The above and other obiects and advantages Vof the invention will appear more fully hereinafter 'from a consideration ofthe detailed description which follows, taken together with the accompanying drawing wherein one embodiment of the invention is illustrated. It is to be expressly understood, however," that the drawing is for the purpose of illustration, only and is not to be construed as defining the limits of the invention,

this purpose.

The invention consists susbtantally in the cona struction, combination, location and relative arrangement of parts for obtaining the results' desired in accordance with the' foregoing objects, as will be more fully vhereinafter lset forthin the specication, as shown inthe drawing, by way of example, and as finally pointed out in the claims.

In the drawing wherein like reference characters refer vto like parts throughout the three views, y I

vFig. 1 is a'pla'n view of a portion of an aircraft, showing, more or less diagrammaticall'mone ar-v rangement 'Uf elements embodying the novel combination of the present invention; Fig. 2 is a detailedsectional view of -a solenoid valve automatically controlled in l accordance with the present invention for rendering the deicing mechanism operative; andi f Fig. 3 is a vertical section of one form of automatic control device by means of which the solenoid valveof Fig. 2 is controlled and operated to controlthe d e-icing Ymechanism.

Referring to the` drawing and more particularly Ato Fig.' 1, Athere is shown, in plan view, aportion of an airplane! having wings 5 and 6 provided with ice overshoes 1 and 8 atthe leading edges thereof. Air under pressure for inilating thev air cells or overshoes '1 and Bis preferably derived from an engine driven pump9 driven by the engine l0. Each of the shoes used may be provided with a separate pipe for supplying the air thereto from the pump 9 bui-in thecform illustrated,

Aa distributor il is employed which is connected to the pump 8 through anoil separator I2 by means of pipe connections I8, I8 and i8 and is provided with three outlets I8, i1 and I8, the

outlets I8 and i1 being connected to the overshoes 1 and 8 on the wings 8 and 8 and the outlet I8 being connected to an overshoe or overshoes provided on ,the leading `edges of the tail structure (not shown) of the airplane. The distributar lis driven'l by an. electric motor (not shown) energized from a suitable source of electricalv energy such 'as a battery I8 when the purpose of`which will appear hereinafter, and,

manually operated-switch 28 is closed.l 'I'he negative side of the battery is grounded-at 2| land the positive side .is connected through the switch 2Ii.to one side of the distributor motor and the other side of the distributor motor is connected through a winding 22 of a solenoid valve 28, the

through a' signal devicesuch as a lamp 28 which is in parallel with the winding 22. 'I'he circuit of winding 22 and lamp 28 is completed to ground through an automatic switch which will be described hereinafter.-

In operatiomjpunip 8 drives under pressure to the distributor Iifrom whichit is supplied in sequence-'first toovershoe 1, -then to ovrshoe p structure, and'isV exhausted,A then to the atmos-v 8, and to lthe overshoe or. overshoes ,onthe tail phererby means' of'anexhaust pipe 28all in the j manner shown and describedvinjthelaforementionvedv Patent N0. 1,890,886;

Means arev now provided for automatically "controlling the `deicing,mechanism whereby-the latter is automatically rendered operative when ice begins toy form on `,the surfacesfof the aircraft.

. Inl'thev form 'shown said means include the sole- 'noia valve arrondiI a device' 21 mounted on the wing 8 so thatsaid device is in thepath 'of the slip stream.' Saidv ldevice includes the aforementioned automatic switch indicated. at 28 whichj is normally open but lis automatically closed, in'a manner vto be described later, when ice -forms atthefront ofthefdevice 21 whereby the solenoid valve 28 is actuated to closed position.

Normally the pump`8 exhausts directly tothe at;v

lmosphere by means -ofan exhaust pipe 28, said pump 8 being connected to the' solenoid valve 28 by means'of a'pipe' 88.. Therefore, one side of` the automatic switchv 28 is connected to thev vground at 8i and the other sideis connected to the winding 22 'of the solenoid valve 28 as here;

. inbefore stated. u

.. l'Ihe solenoid valve is shown in htail section to an adjustable nut 88 threaded in an extension 88 of the housing 82 and the other end of said spring is secured to the end of the valve stem 8i c f the valve memberI 88. The valve stem 8l is ofmagnetic material such as soft iron and constitutes a plunger vof the solenoid formed by coil 22 which is woimd on a sleeve 82. through whichl the. plunger 8l extends. 'lhe ends of the coil 22 are connected to the terminal bindingv posts 88 and 88 by means of which the coil 22 is connected to the device 21 and the battery i 8 through the distributor I I.

Normally, the passage 88 is open, as shown, with the valve member 88 suspended from the spring 88, so that the pump 8 is connected to the atmosphere through said passage 83 and exhaust pipe 28. whereby the pump is ineffective to supply air pressure to the distributorl Ii and, hence, to the @overshoes or de-,icers. When the automatic switch 28 of the device 21 is closed, however, the coil or winding 22 becomes energized thereby operating the plunger 8l by a downward magnetic pull against the pull of the coil spring 88, thus closing the passage 88, whereby the pump is then eiective to supply air to the overshoes through the distributor which, as previously stated, inflates the shoesin a cyclic sequence in a manner described and claimed in .the aforesaid Patent No. 1,990,866 whereby when. one overshoe'is inflated the second overshoe is partially inflated and the third overshoe is deflated, each overshoe becoming inilated in turn.

A by`pass 88 is provided which communicates with the passage 88 on opposite sides koi' the valve seat 81. The by-pass 88 risriormally closed by meansof the valve member 88 'which is held in closed position by means of a coil spring 81 one end of which abuts the valve member 88 and the other end of which abuts an adjustable nut 88 whichisgprovided for.-"regulatingthe pressure at .which the valve 88 may automatically open.

The valve 88 constitutes a .relief valve for releasing the air to the atmosphere when the pressure in' the pumpexceeds a predetermined, limit determined by the adjustment of the spring 81 and when the valve member 88 is in closed position, Lne., when the de-icing mechanism 4is operating.

y -Theautomatic control device whichl is responsive to'lce formation is shown in sectional detail in Fig. 3 and is disclosed and claimed in o o-pend-v ing application of Paul Leifheit, Serial No. 54,486, v

. med of even date herewith, butggenerally, said device comprises a 'stream-lined tubular member 88 which mergesr into a separate stream-lined compartment 88 formed bya tapered end 8| and a blunt, front end` 82 facing the direction of travel of the airplane, and also by side walls '(n'ot shown).l The device is carried by a stream-lined y mounting bracket 88 by means of which said devicemay be mounted on the wing 'of the airplane as shown in Pig. 1 so that' when the aircraft isin night. air enters at the left end of the tubular member 88, as viewed in Hg. 8, passes therethrough and out of said member.

` Within the tubular member 88 and in the. path of the air passing therethrough there is provided a member in the form of a paddle yhaving a circular portion 88 and an integral arm 88 which projects into a slot 88 provided in the bottom wall of the tubular member 88 and into the compartment 88. The arm .88 is pivoted on a shaft 81 the ends of which are secured in the side walls l of the compartment 88 so that as air rushes through the tubular member 88 the circular portion 88 of the paddle is moved in the direction of the arrow shown in Iig. 8 against the compression of a coil spring 88 one end o'f which abuts the end.88 of the paddle arm 88 and the other endofwhichisfastenedtoascrewinthe front 'wall 82 o8 the auxiliary compartment `88.

is provided a\ contact finger 8i carrying a contact 82 which is adapted to cooperate with a rela- AOn the opposite side of the paddle arm 88 there tivelyilxed or stationary contact 88 carried by an 18 adjusting screw 64 secured in and passing' through the rear end and insulated therefrom by means of an insulating bushing 65.

The contact 63 is connected to a Wire 66 by means of a terminal lug secured to the adjusting screw 64 by means of a nut 61. Contact 62 is grounded by virtue of its connection to the finger 6I and arm 55 which for this purpose are made of metal as is the shaft 51 and the tubular mem-'- ber 49 and the mounting bracket 53. If, however, the mounting bracket 53 cannot be mounted on a grounded portion of the aircraft then the groufid connection is provided by means of a wire 69 one end of which is connected to the portion 5I of the device by means of a screw 18 and the other end of the wire 69 is connected to the ground 3l as in Fig. 1. r

The coil spring 58 tends to urge the end 59 of the arm 55 to the right as viewed in Fig. 3 to cause the contact 62 to engage contact 63 thereby tending to close the circuit to the winding 22 of the solenoid valve 23 and to the signal lamp 24 when the manually operated switch 20 is closed. Normally, however, when the device is mounted on the wing of the aircraft, as shown in Fig. 1, the rush of air through the tubular member 49 urges the circular portion 54 of the paddle in the direction of the arrow, as shown in Fig. 3, against the compression of the spring 58 thereby maintaining the contacts 62 and 63normally open. Thus, the contacts 62 and 63 constitute the automatic switch 28 referred to hereinbefore and shown generally in Fig. 1.

Means are now provided whereby the rush of air through the tubular member 49 is prevented when ice forming conditions exist and, as illustrated, said means comprise a fine /wire mesh screen 1| placed over the front end of the tubular member 49, said screen being securely held in place by means of a clamping ring 12 secured to the tubular member 49 in any suitable manner as by means of screws 13. Thus, as sleet and/or ice form on the screen 1i, the passage through the tubular member 49 becomesblocked either partially or entirely whereby the air pressure on the circular portion 54 of the paddle is-reduced or eliminated so that the coil spring 58 urges the contact 62 into engagement with the contact 63 to close the electrical circuit to the winding 22 and signal lamp 24 thereby giving a warning signal and automatically starting the de-icing mechanism in operation to periodically inflate and deflate the overshoes 1 and 8 which, as previously stated, are of rubber fabric so that the stretch of the fabric breaks the ice JJvhich is then carried away by the airmstream.

The signal lamp 24 is preferably mounted on the instrument panel (not shown) of the aircraft so that the pilot may readily observe the same when a signal is given; The signal lamp, however, isnot necessary to the operation of the de-icing mechanism.

There is thus provided a novel combination including a de-icing mechanismand a device eX- y posed to the atmosphere for automatically operating said de-icing mechanism when ice forming conditions exist and ice begins to form on the wings of the aircraft whereby accumulation of ice on said wings is substantially eliminated and/or prevented.

Although only one embodiment of the invention has been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear to those skilled in the art, may be made Without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. In combination, an aircraft, de-icing mechanism including inflatable members on the surface of said aircraft for preventing accumulation of ice on said surface, means for periodically inflating said inflatable members, and means on said surface and responsive to ice formation for automatically controlling inflating means.

2. In combination with an airplane, a source of fluid pressure, a plurality of expansible members secured tolthe plane structure, means for periodically connecting the members with said source,

4. In combination with an airplane, a source of fluid pressure, a plurality of expansible members secured to the plane structure, means for periodically connecting said members with said source, and means on said plane structure and responsive to ice formation on said structure for automatically controlling said connecting means.

5. In combination with an airplane having an 4engine driven pump, a plurality vof expansible members secured to the plane structure, a distributor valve for supplying fluid under pressure from said pump to said expansible members, means normally rendering said pump ineffective to supply fluid under pressure, and means responsive to ice formation on saidplane structure for automatically actuating said last-named means whereby said pump-is rendered effective to supply fluid under pressure to said expansible members through said distributor valve.

6. In combination with an airplane, a plulrality of expansible members connected to the plane structure, an air pump, means for driving said pump, an electrically operated rotary distributor valve for connecting said pump to said expansible members, a solenoid valve normally rendering said pump ineffective to pump air to said distributor valve, an electric circuit including said rotary distributor, said solenoid valve and a source of electric current, and means responsive to ice formation on said plane structure for rendering said circuit effective to cause actuation of said rotary distributor and solenoid valve whereby -said pump supplies air under pressure to said expansiblemembers through said distributor,

HOWARD E. BAER. 

